Control system for gun mounting and other mechanism



Nov. 6 1923. 1,472,885

A. L. PERHAM CONTROL SYSTEM FOR GUN MOUNTING AND OTHER MECHANISM Filed June 13. 1923 Patented Nov. 6, 1923.

UNITED STATES PATENT OFFICE.

ARTHUR LEONARD PERHAM, OF WESTMINSTER, LONDON, ENGLAND, ASSIGNOR TO VICKERS LIMITED, OF WESTMINSTER, LONDON, ENGLAND.

CONTROL SYSTEM FOR GUN MOUNTING AND OTHER MECHANISM- Application filed June 13, 1923. Serial No. 645,081.

To all ril /10m, III 772/{1/ mic/I'll.

Be it known that L Am'ni'n LEONARD PBRHAM, a subject of the King of (treat Britain, residing at \iickers House. Broadway, lVestminster, in the county of Londoln England, have invented certain new and useful Improvements in or Relating to Control Systems for Gun Mounting and Other Mechanism, of which the following is a specification.

This invention relates to control systems for gun mountings and other mechanism particularly to systems of pointing ordnance in which the gun or guns are controlled in elevation or training, or in both clevation and training, from a sighting or controlling element arrangedat a distant (or central) station and in which there is employed a rc-- ceiving or indicating member or pointer drivenlby electrical means in synchronism with the vertical or horizontal movements oi the distant sighting or controlling element; the said member or pointer is preferably arranged to rotate about the same axis as a follower member or pointer driven mechanically through multiplying gearing from the n. I The gun is fitted with some form of motor for elevating or training (such motor being preferably hydraulic or being constituted by the motor unit of an hydraulic transmission device of the Janney type as this allows of exact adjustment of speed control) and power operated means are arranged to actuate the lever, valve or other device for con trollingthe speed and direction of movement of the elevating or trainingmotor. these means being hereinafter referred to as the relay. This relay may be of any convenient type and is preferably arranged to be brought into operation by electromagnetic means under the control of a switch, so that-when the arm of this switch is displaced to one side or the other of its central position, a corresponding movement. of the relay in one or other direction takes place. thus operating the control device of the elevating or training motor. The switch controlling the relay is arranged to be itself brought into action whenever the receiving and follower members are out of alignment. Instead of an .electrical switch, a mechanical device havin similar characteristics of bringing the re ay into operation and cutting it out of operation may be used and the term switch is intended to include this and similar arrangements.

The chief object of the present invention is to devise a control system which simpler in construction and operation than that forming the subject of the prior English Patent No. 16295 of 1911 and in which, in particular. the receiving member is purely rotary and does not require to move axially to )ertorm its proper function.

'lhe switch is so constructed and arranged that when relative displacement occurs between the said receiving and follower members and the switch is actuated in consequence, the resulting movement of the relay will act upon the switch so as to stop the relays own movemenh the arrangement being such that the greater the relative displacement between the receiving and follower members, the greater distance mustthe relay travel in order to open the switch, and according to the present invention we provide means whereby the ratio of relay movement to relative displacement between the receiving and follower members decreases as the latter *increases. According] we preferably arrange that the movab e switch arm shall be controlled by a cam the movement derived from which varies with the amount of the relative displacement between the receiving and follower members.

The action of the apparatus is that the gun always follows behind the receiving member if the latter is in motion, the gun slowing u and stopping in line with this member wlienvthe latter stops. This effect is desirable when it is intended to stop elevating or training the gun at or about the moment of firing. But in some cases, particu larly with guns mounted on land, it may be desirable that at all speeds of elevating and training, the receiving'and follower members shall always be in exact alignment, and in this case we slightly modify the construction of the apparatus to secure absence of angular lag; the means employed for ohtaining this effect may comprise a dash-pot device which is preferably capable of being put out of use when desired or of being employed only with those speeds of elevating and training at which continuous aiming is practicable. We may also employ a lost motion coupling in the connections between the relay and the switch so as to provide against lag occurring by reason of the lap meat-being such that when lit) of the elevating or training control valve in cases where hydraulic power is used.

In order that the said invention may be clearly understood and readily carried into effect the same will bemorc fully described with reference to the accompanying drawings in which Figure 1 is a sectional view of apparatus constructed in accordance with the invention, the relay control element being omitted from this figure, and

Figure 2 is a view showing the said relay control element and also shewing the'front view of the receiving and follower members and the cam actuated switch arm together with the switch and its contacts.

It will be assumed that the a paratus shewn is intended for controllin t e training of the gun and will be descri ed in this connection, it being understood however that the said apparatus is also applicable to the elevation control and also to the control of searchlights, range finders and other apparatus.

A is the receiving or indicating memberv in the form of a pointer mounted on a spindle a which is geared to a step-by-step electric motor A. This motor is o erated from the distant sighting or contro ling station in accordance with the up lie of training to be given to the gun. B is t e follower member in the form of a disc mounted o a shaft 5 which surrounds the spindle a and is driven through multiplying gearing from,

gun. his disc has omter' B which is opposite the pointer 1 training part of the an index mark or brought or maintain A by training the gun. is the switch, C is the switch arm which is pivoted at 0' to the disc B and D is the cam which operates upon the switch arm and is w pointer A t In the construction shown the control valve E of the training motor is connected to a relay piston E working, in a cylinder E" one end of which is in constant communication with pressure fluid through a port e and the other end of which is connected to a ipe e leading to a valve chamher E. T e relay control element comprises two electro-magnets e, e which are electrically connected to the contacts on'the switch C nd th armature e of which opcrates upon one o the other of two, valves e, a" controlling the supply and exhaust of pressure .tluidto andfrom the relay cylinder E through the pipe e, the arrangethe switch arm C moves in one direction the valve 0 will he moved from its seatto admit pressure fluid to the relay cylinder E5. and when the said switch arm moves in the other direction the valve e will be moved from its seat to exhaust pressure fluid from the relay cylinder, the' valve E being displaced acrelay piston cordingly in one direction or the other. The stems of the valves 6, a pass through the cores of the electro-magnets e, e in order that the armature 6 may operate them, and adjustable needle valves e, e are provide for adjustin the rate of movement of the J. A spring a operating on one of the limbs of the armature 6 serves to prevent the armature from remaining in a balanced position when both the magnets are energized this being a condition which occurs when two pairs of iiidicating and follower members (one pair moving at a greater speed than the other) are used instead of one pair as is described in the specification of the aforesaid prior patent.

The cam D that operates the switch arm C is so formed that the movement of the switch arm is not in direct proportion to the movement of the pointer A and to fa'cilitate as far as possible the experimental work of obtaining a suitable cam shape we make the cam re' dily detachable and cut it from a sheet oi thin stiff material such as metal or fibre so ythat diflerentprofiles of cam can quickly andcheaply be cut out and tried.

The relay pi'ston E may be directly connccted to a bell-crank lever G (although in the example shown it is indirectly connected thereto through mechanism which will be hereinafter described) which operates upon a collar (i' having a pin 9 enga ing in a curved slot 5' in the aforesaid s aft b of the disc B and also engaging in a straight slot 0 in a sleeve C which is connected to the switch C and is interposed between the collar (l' and the shaft b. This islthe arrangement whereby the relay acts upon the switch C to break the circuit through the elcctro-magnets e e in order to stop the movement of the relay.

In the example'shown there is a dash-pot ll in the connections between the relay piston E and the bell-crank lever G for the purpose of preventing angular lag between the gun and the pointer A as aforesaid. The stroke of the dash-pot may be limited by adiustahle stops h hon the piston and cylinder and a pin H" is provided for connecting the piston rod to the cylinder when it is desiredto place the dashpot out of action and obtain the said angular lag. An adjustable screw H is provided on the dashpot to'control the rate of leakage of the fluid from-one side of the piston to' the other. The cylinder is controlled by a soriug fi'andithe bell-crank lever G is under theycontr poi a eentering ipring H than the spring I In order to provide against lag occurring by reason of the lap of the control valve E as aforesaid, an adjustable lost-motion coupling H is provided between the stem cylinder of the dash-pot.

The operation of the apparatus is as follows: Assuming the receivin pointer A to move to the left (Figure 2) t e eam 'D carried by this pointer operates the switch arm C and moves 'it on to the ri ht hand contact strip of the switch C. T e valve of of the relay controlling mechanism is thereby opened and the lower part of the rela cylinder E thereby placed to exhaust. he relay piston E is thus moved downwards under the influence of constant ressure in the upper art of the cylinder E x and the control va ve E is consequentl opened to operate the prime mover whic drives the disc B so as to cause the mark B to follow the movement of the receivin pointer A. Theswitch C is carried roun with the disc B as is also the switch arm C, but in order to Stop the movement of the relay piston E the latter 0 rates through the pin g and the slots ca to displace the switch C relatively to the disc B so as to bring the latter to the neutral position in which the switch arm C lies between the two contact strips .of the switch and so brings the relay to rest,

in which condition the said disc, switch and switch arm continue to rotate so long as the pointer A is movin connection between t e parts E' and G (i. e., if the aforesaid dash-pot H is put out of action), the pointer A will be continually in advance of the mark' B. When the pointer A stops moving the disc B continues to move for a time and im' so doing the switch arm C is moved on to the left hand contact strip of the switchU and the relay piston E' is therefore moved in the reverse direction to that mentioned above and the control valve E thereby moved towards the closed osition during which' time the switch C is a so moved in the reverse direction to that mentioned above and the control valve therefore brought to rest in the closed posi tion with the pointer A opposite the mark B.

If the switch arm C were rigidly connected to the pointer A the amount b which it would always move away from t e neutral .point of the switch C and therefore the pointer A stops, the aforesaid cam D is in troduced for operating the switch arm C and is'so formed that the latter instead of moving in exact pro ortion to the relative movement between t e pointer and the mark B as mentioned a ove is given a reduced movement so that the who of relay If there is a rigid! movement to relative displacement between the receiving and follower member (viz, the pointer A and the dis B) decreases as the latter increases.

When the dash-pot H is in use the operation is modified in the following respect, it bein understood that the action of thecam D, t e switch arm C and the switch C is exactly the ame as that described above. With the dash-pot in use it will be evident that there is a movement of the relay piston E which isnot transmitted through the pin 9 and the slots 0 b to the switch C with the result that a lag is introduced which ermits the switch C to move with the disc further than it otherwise would have done and this results in the mark B being permitted to catch up with .the pointer A before the switch C has been returned to the cut off position and the relay thereb brought to rest with the control valve 1 open. The parts B, C, C and D then continueto rotate in exactly the relative ositionshown in Figure 2 and when the pointer A stops the mark B overrunait and reversal has to take place in order to restore alignment.

The lost motion device H is for the urpose of permitting a small initial and nail movement of the'relay piston E to occur in order to take up the lap of the control valve E without such movement s bein transmitted back to the switch C. Obviously as th movements of the control valve in taking up the lap are ineffective for the purpose of controlling the prime mover, such movements must not be taken into account in connection with'the cutting ofi of the relay and the lost motion device H ensures that this shall be so. The centering spring H restores the parts to the central position when the apparatus is stationary.

Although in the construction shewn there is a mechanical connection between the relay piston E and the switch, it is to be understood that any other suitable arran ement may be employed for causing t e switch to be moved in accordance with the movements of the said piston.

Instead of the aforesaid form of followthe-pointer mechanism involving the use of the pointer A and the index mark or pointer B, an equivalent arrangement involving the use of a balanced pointer may be emloyed; in this arrangement (which is in itself well known) a receiving member operated from the distant sightin or control ling station and a follower mem er operated by the gun are connected to a single balanced pointer through differential or epicyclic gearing, this balanced ointer remaining opposite a fixed zero mar so long as the follower member correctly follows the movement of the receiving member.

It is to be understood that the expression controlled element in the claims is intended to cover the part of the apparatus wh1cli is moved or'trained, for example, in the case of ordnance the gun itself, or in the case of remote control searchlights, the Searchlight itself, &c.

What I claim and desire to secure by Letters Patent of the United States is:

1. In a remote control system the improvements which comprise a movable receiving member, a follower member connected with the controlled element, a relay, a relay switch, means for operating said switch by the relays own movement so as to open the switch and stop the movement of the relay, and means for decreasingathe ratio of relay movement to relative displacement between receiving and follower membersas the displacement increases.

2. In a remote control system the improvements which comprise a movable receiving member, a follower member connected with the controlled element, a relay, a relay switch, means for operating said switch by the relay-s own movement so as to open the switch and stop the movement of the relay, and means for preventing angular la between the receiving member and the fol ower member.

3. In a remote control system the improvements which comprise a movable receiving member, a follower member connected with the controlled element, a relay, a relay switch, means for operating said switch by the relays own movement so as to open the switch and stop the movement of the relay,

an adjustable dash-pot device interposed between the relay and the switch opening means to prevent angular lag.

4. In a remote control system the improvements which comprise a movable t'eiving member, a follower member connected with the controlled element, a relay, a relay switch, means for operating said switch by the relays own movement so as to open the switch and stop the movement of the relay, an adjustable dash-pot device interposed between the relay and the switch opening means to prevent angular lag, a lost motion coupling and relay centering spring.

5. In a remote control system the improvements which comprise a movable receiving member, a follower member connected with the controlled element, a relay, a relay switch, means for operating said switch by the relays own movement so as to open the switch and stop the movement of the relay, and means for decreasing the ratio of relay movement to relative displacement between receiving and follower members as the displacement increases an adjustable dash-pot device interposed between the relay and switch opening means to prevent angular lag, a lost motion coupling and a relay centering spring.

6. In a remote control system a movable indicating pointer, a concentric follower member positively connected with the controlled element, a disc concentric with the follower and rotating with it, a relay switch on said disc, a switch arm pivoted on the follower and bearing on a cam rigidly attached to the pointer, said switch and cam being so proportioned that the ratio of relay movement to relative displacement between receiving pointed and follower member decreases as the displacement increases, a

slide valve operated by the relay, a dashpot device connected to the valve slide through an adjustable lost motion coupling, and means for rotating the switch disc with respect to the follower, saidmeans being operated by the valve slide through the dash-pot device and lost motion coupling.

ARTHUR LEONARD PERHAM;

Witnesses:

S. Manes, BASIL Mansn. 

